Sometimes, as parents often remind children in their youth, two wrongs don’t make a right. This held true on Tuesday, when Democrats erupted over comments by Senate Majority Leader Mitch McConnell (R-KY) on entitlement reform.

In returning to “Mediscare” tactics, Democrats made several false claims about entitlements. But so did McConnell, who blithely omitted what a Republican majority did earlier this year to worsen the country’s entitlement shortfall.

What McConnell Got Wrong

In an interview with Bloomberg earlier this week, McConnell claimed that the significant increase in the deficit this past fiscal year “is not a Republican problem. It’s a bipartisan problem: Unwillingness to address the real drivers of the debt by doing anything to adjust those programs to the demographics of America in the future.”

McConnell spoke accurately when he said in an interview that Medicare, Social Security, and Medicaid serve as the primary drivers of our long-term debt. He stood on less firm ground when he told Bloomberg that “the single biggest disappointment of my time in Congress has been our failure to address the entitlement issue.” Contra McConnell’s claim, Congress—a Republican Congress—actually did address the entitlement issue this year: they made the problem worse.

This Republican Congress repealed a cap on Medicare spending—the first such cap in that program’s history. It did so as part of a budget-busting fiscal agreement that increased the debt by hundreds of billions of dollars. It did so even though Republicans could have retained the cap on Medicare spending while repealing the unelected, unaccountable board that Democrats included in Obamacare to enforce that spending cap.

By and large, both parties have tried for years to avoid taking on entitlement reform. But Democrats included an actual cap on Medicare spending as part of Obamacare, and Republicans turned around and repealed it at their first possible opportunity. That makes entitlements not just a bipartisan problem—it makes them a Republican problem too.

What Democrats Got Wrong

Following the McConnell comments, liberal Democrats gleefully ran to Twitter to claim that Republicans were “coming after your Medicare:”

But McConnell’s comments suggested just the opposite. He noted that, while entitlements serve as the prime driver of the nation’s long-term debt, any changes to those programs “may well be difficult if not impossible to achieve when you have unified government.” McConnell said the same thing in a separate interview with Reuters on Wednesday: “We all know that there will be no solution to that, short of some kind of bipartisan grand bargain that makes the very, very popular entitlement programs in a position to be sustained. That hasn’t happened since the ’80s.”

Even though Congress needs to start reforming entitlements sooner rather than later—even if that means one political party must take the lead—McConnell indicated he would do nothing of the sort. In fact, his comments implied that Congress would not do so unless and until Democrats agreed to entitlement reform, giving the party an effective veto over any changes. Yet Democrats, who never fail to demagogue an issue, attacked him for those comments anyway.

House Minority Leader Nancy Pelosi (D-CA) went one further. Not only did she issue a press statement claiming that “Republicans are setting in motion their plan to destroy [entitlements]”—when McConnell’s comments suggested just the opposite—she went on to claim that “under the GOP’s twisted agenda, we can afford tax cuts for billionaires, but not the benefits our seniors have earned.”

Actually, they haven’t “earned” those benefits. Seniors may have “paid into” the system during their working lives, but the average senior citizen receives far more in benefits than he or she paid in taxes, and the gap continues to grow.

Making a Tough Job Worse

In this case, two wrongs not only did not make a right, they made our country worse off. Like outgoing Speaker of the House Paul Ryan (R-WI), McConnell wishes to absolve himself of blame for the entitlement crisis, when he made the situation worse.

On the other side, Pelosi and her fellow Democrats continue the partisan demagoguery, perpetuating the myth that seniors have “earned” their benefits because they see political advantage in defending nearly infinite amounts of government subsidies to nearly infinite numbers of people. For all their love of attacking “science deniers,” much of the left’s politics requires denying math—that unsustainable trends can continue in perpetuity.

Likewise, the media provides little help enlightening the American people about the fiscal mess our country faces. Despite a focus on health policy during the midterm election campaign, I fail to recall any stories demonstrating how seniors haven’t really “earned” all the entitlement benefits they receive.

At some point, this absurd game will have to end. When it finally does, our country might not have any money left.

Mr. Jacobs is founder and CEO of Juniper Research Group, and author of the forthcoming book, "The Case Against Single Payer." He is on Twitter: @chrisjacobsHC.